Garden Pests and Diseases: What’s wrong with my tomatoes?, 3 by Sendit

Sendit wrote:
Something is obviously wrong with my tomato plants. One plant started getting this interveinal chlorosis which started at the bottom but spread up the plant at rocket speed. It seemed to run up the interior of the plant before spreading towards the outside. It’s started to spread into the other plant in the 4’x8’ bed and has even begun to appear in a different raised bed, 5’ away. The soil is pretty rich and fairly well balanced; so I don’t really think it’s a nutrient deficiency, and definitively not a lack of nitrogen in the soil. My suspicion is that it’s a fungal disease. I tried treating it with Marrone Bio’s Grandevo but that didn’t have any effect. I take pride in my organic gardening but I can’t afford to lose these plants. So, I bit the bullet and sprayed some Daconil (Chlorothalonil) on them - it hurt me to do it but not quite as much as losing these plants. I WOULD like to know what they have, for future reference, though. I’ve had this garden for 2 years before this season and I haven’t had this issue before.

It’s been VERY warm over the past few weeks (up to 100° on some days) and we have had some periods of rain that raised our humidity periodically.

Any help y’all can give me would sure be appreciated!